Maximum Flexible Duct Length Smacna

Proposal to limit use of flexible duct has many in HVAC industry upset An International Association of Plumbing and Mechanical Officials committee has approved a change to the group's Uniform Mechanical Code, limiting the use of flexible ductwork to 5 feet or shorter runs. , GRPFRO3VGA50 at Zoro. Fibrous duct construction shall conform to the SMACNA Fibrous Glass Duct Construction Standards or NAIMA Fibrous Glass Duct Construction Standards. 2 ROUND DUCTS AND FITTINGS A. In order to give contractors solid information on what needs to happen for a satisfactory. Provide long-radius elbows (R/D = 1. EASTERN TIGHT Fittings have been tested in our standard gauges for -2" to +10" WG and have been used to meet SMACNA Class 3 leakage standards. Ducts should be insulated in accordance with ASHRAE Standard 90. The smooth, black, acrylic- coated surfaces of the Permacote Linacoustic HP shall face the airstream. The airstream surface is protected with Permacote®, a state-of-the-art acrylic surface coating system. concrete advice on sizing medium-pressure VAV duct mains, the EDR. UNILOK FR1 Acoustic Ducting is a flexible duct manufactured "tough" & "whisper quiet" for consumer & installer peace of mind. Each branch should have a balancing damper installed. ) the rigid duct would leak about 8 CFM or 1. Certain Connectors are available with 300L series or 316L series stainless steel or aluminum. Assumptions are consistent with these tables (i. Do not install in the compressed state or use excess length. ROUND DUCT DIAMETER. The UPC #037 inner core is air-tight and is designed for low-to-medium operating pressures in HVAC systems. flex duct sizing smacna length. The maximum duct velocity is found from Table 4. static pressure class and 2500 FPM maximum velocity. connections. The amount of leakage at a specific pressure is calculated by measuring the amount of air that is measured as it is blown into the closed duct system. Connect diffusers or light troffer boots to ducts with maximum 60-inch (1500-mm) lengths of flexible duct clamped or strapped in place. Since all flexible ducts are not alike, use the flexible duct manufacturer’s air friction loss data to size the ducts whenever possible. Suitable for use with ducted reverse cycle air conditioning, ducted gas heating and evaporative cooling. Flexible Ductwork a. 17 Total joint length Length (m) of joints resulting from the installation of the ductwork, that is the sum of each joint perimeter. Figure 5 - Installing Flex-Duct on Tube Connect Flex-Duct to Duct System Connect the 152 mm end of the flex-duct to the duct system. for longer lengths, increase the duct size and provide a duct transition to maintain the duct static pressure drop at or below 0. all flexible duct shall conform to the requirements of u. Constructed with all aluminum ribbon, DryerFlex fire-rated duct is as flexible as "slinky" foil flex yet stronger than semi-rigid aluminum, making installation easier and every laundry room safer. R = Reinforcement ring at 12’ maximum spacing. In most cases, local regulations limit their length to a maximum of 1. out-lines a relatively simple duct sizing technique called the Friction Rate Reduction Method. Most technicians are skeptical about these numbers, especially on the Return air side of the system. SMACNA CAD Standard Second Edition v NOTICE TO USERS OF THIS PUBLICATION 1. ™ Never locate a takeoff in the end cap. The shower is on one side of the room and the bath is on the opposite wall so I plan to put the fan in the middle of the room. END OF SECTION 15820. Mathematics and pages. insulated flexible duct. Application Limitations. 5m),it may keep its circular shape and possibly may not need to support it. Provide flexible duct runs as short and straight as. adairinspection. Step 3:Aluminium Tape Application Using minimum 2. Standard roll length - 100 ft. Connect diffusers with maximum 120-inch lengths of flexible duct clamped or strapped in place. wg, to 36 in. ricate, install and commission. connections. This section provides for furnishing and installing low velocity and high velocity ductwork and includes duct construction and accessories. Get info of suppliers, manufacturers, exporters, traders of Spiral Duct for buying in India. 003 ft when straight and fully stretched tight at 0% compression (adjusted at other compressions), otherwise the. Model # Diameter Carton Qty. Individual fittings may not have reinforcement. Metallic Silver Polyethylene Duct Tape Shurtape SF 682 2 in. Semi-rigid spiral locking flexible duct is preferred for connection to terminals. In some applications, bracing may be required. SMACNA Ducted Electric Heat Guide for Air Handling Systems 2. Th is table is presented as an allowable leakage specifi cation but it is still based on SMACNA leakage classes. Appliance411 FAQ: How long can my dryer vent be? The maximum length for a dryer vent varies greatly between brands and models. A good rule of thumb is to provide a duct support no less than every 4 feet, and more frequently when using large-diameter flexible duct [4C], even when ducts are partially supported by framing members [4D]. Connect terminal units to ducts directly or with one-foot maximum length of flexible duct. 1 Toll Free (USA Only): 800-959-1229 RELEASED ON: 07/07/2008. Shop a large range of black 7 inch hose at MSC Industrial Supply. • Insulation R-value to meet Energy Code. Measure the length of straight duct. HVAC Ducting Accessory improves air flow and saves energy by eliminating sags and kinks. see specifications for gauges, thickness, bracing, requirements, etc. the following conditions is met for the full length of each duct run: » 1. When you change the setting in mechanical settings > Duct settings > Branch - Make sure that all the system types have the maximum flex duct length increased. Chapter 4101:2-6 Duct systems. TDC (Transverse Duct Connection): As per duct manufacture catalogs is a flange constructed from the main duct sheet which means it is attached to it it has the same duct gauge TDF (Transverse Duct Flange): Is on based to the construction standards follow SMACNA. Our goal is to maintain a long-lasting relationship with our clients based on exceptional HVAC, Piping & Plumbing Shop Drawings. , 1995,it was found that in some tests, the Ward Angles (E,H and J) permitted a more liberal interpretation of the SMACNA Tables. SMACNA HVAC Duct Constructions Standards Questions Part 1 1. The maximum length of the exhaust duct shall be 35 feet (10 668 mm) from the connection to the transition duct from the dryer to the outlet terminal. The SMACNA Testing & Research Institute conducted a comprehensive evaluation of the submittal as an acceptable alternative for use with the SMACNA HVAC Duct Construction Standard - Metal and Flexible, 2nd Edition 1995. Connect diffusers to low pressure ducts directly or with 10 feet (3. Flame test 25 maximum and smoke developed 50 maximum. 2 ADJUSTING. GUIDE TO MAXIMUM AIR VELOCITIES IN DUCTS Leaflet L115 Page 1 of 1 issued 07/08/01 When considering the acoustic design of a ventilation or air conditioning system, it is important to take into account noise. 1—2012 Australian Standard® Ductwork for air-handling systems in buildings Part 1: Flexible duct AS 4254. UNIVERSITY SERVICES ANNEX James Madison University Harrisonburg, Virginia State Project Code: 216-18135-000 Architect’s Project Number: 545116 AIR DUCT ACCESSORIES 233300 - 4 b. 17 Total joint length Length (m) of joints resulting from the installation of the ductwork, that is the sum of each joint perimeter. is allowed. General Fabrication Requirements: Comply with SMACNA's "HVAC Duct Construction Standards - Metal and Flexible," Chapter 3, "Round, Oval, and Flexible Duct," based on indicated static-pressure class unless otherwise indicated. QuietR® Duct Liner products shall be cut to assure overlapped and compressed longitudinal corner joints. Use the minimum length of flexible duct to make connections. 5 times duct width (minimum) on tees, bends, elbows. HVAC Calculations and Duct Sizing Gary D. per ft (42 mm per m). "Length identification. Duct Liner PM Fiber Glass Duct Liner Description Duct Liner PM is a flexible duct liner insulation made from strong, glass fibers bonded with a thermosetting resin. Ductwork can be routed in any direction from the hood transition. Pipe and Duct Run needs a minimum of 2 lateral restraints and 1 longitudinal restraint. That's most often referring to the "2005 SMACNA HVAC Duct Construction Standards - Metal and Flexible". 320 cfm in 8" duct yields. Measure the duct length from the design drawings and check different scenarios as explained above since the index run is the duct run with the maximum external static pressure drop not the. SMACNA HVAC Duct Construction Standards - Metal and Flexible 5. ™ Keep branch run starting collars 24 in. Connect flexible ducts to metal ducts with adhesive plus sheet metal screws. Factors Influencing Duct Design • Equipment Losses • Air Velocity • Duct Material • Duct Size & Shape • Length of Duct 4. Order DUCTMATE 6-1/2" x 50 ft. Standard length - 10ft. Maximum Thermal Conductivity: a. Message 3 of 3 kevinaldo. Comply with SMACNA's "HVAC Duct Construction Standards--Metal and Flexible" for acceptable materials, material thicknesses, and duct construction methods, unless otherwise indicated. 5 m) NOTE: Maximum airflow assumes diffuser is in full open position. Although typically SMACNA ’s HVAC Duct Construction Standards , Metal and Flexible , will. non-metallic duct, with maximum O. Every above ground duct installation needs hangers or supports of some kind. Conform to the requirement in the referenced standards for metal thickness, conduits and tie rod applications and joint types. The length of the flex duct shall not exceed. and replace non-compliant flexible duct at your cost,” says Chick. The advent of flex duct meant that contractors could dramatically reduce the amount of time and skill it takes to install a duct system. Superior HVAC products for the Industrial, Commercial and Institutional Construction Industry. flex duct sizing chart 8 inch. Duct systems serving heating, cooling and ventilation equipment shall be fabricated in accordance with the provisions of this section and ACCA Manual D or. How to place an order with NYC SMACNA: Complete Part 1. Sheet metal materials shall be free of pitting, seam marks, roller marks, stains, discolorations, and other imperfections. Since all flexible ducts are not alike, use the flexible duct manufacturer’s air friction loss data to size the ducts whenever possible. (+) indicates positive pressure use only. in reply to flex duct length 6' max. connections. This Excel template can be used to calculate velocity and friction loss in air ducts. LJ Assemble, join, install, and repair all types of duct. SMACNA "HVAC Duct Construction Standards Metal and Flexible" 1985 edition. To calculate allowable leakage, you must know the system surface area, the required test pressure and the specified leakage class. scale: none. That's most often referring to the "2005 SMACNA HVAC Duct Construction Standards - Metal and Flexible". Appliance411 FAQ: How long can my dryer vent be? The maximum length for a dryer vent varies greatly between brands and models. We are proactive in helping our customers get the equipment they need. Mechanical fasteners of the speci˜ ed type and length must be used, ensuring no greater than 10% compression of the liner thickness. Fibrous-Glass Duct Liner: Comply with ASTM C 1071, NFPA 90A, or NFPA 90B; and with NAIMA AH124, "Fibrous Glass Duct Liner Standard. Maximum allowable flexible duct length is four (4) feet. Aerocel® EPDM elastomeric sheet is flexible and easy to use for a wide variety of jobs including large air ducts and inside air handling panels. Description Qty Width Height Length Total Length (m) Slot Dimension Neck Slot Collar Collar. Sheet Metal Connectors, Inc. Reducing plenum system The reducing plenum duct system (see Figure 4) can be used when the physical size or layout of the struc-ture calls for greater distances than the length con-straints imposed on the extended plenum (24 ft). Multiply the length and width together to get the square footage of the room. Metal ducts shall be protected from corrosion in an approved manner or. General Fabrication Requirements: Comply with SMACNA's "HVAC Duct Construction Standards - Metal and Flexible," Chapter 3, "Round, Oval, and Flexible Duct," based on indicated static-pressure class unless otherwise indicated. non-metallic duct, with maximum O. Flexible duct shall meet the pressure class requirements of the system served. It is able to endure temperatures between -4°F and +176°F. 5 m/sec) Linacoustic® RC-HP High-Density Fiberglass Duct Liner with Reinforced. unit, and reasonable length duct runs. More comprehensive information on the subject of flexible ducts may be found in the current edition of the Air Diffusion Council (ADC) publication, Flexible Duct Performance and Installation. Smacna Spiral Duct Hanger Detail. 5m),it may keep its circular shape and possibly may not need to support it. Nothing else. SMACNA Fire, Smoke and Radiation Damper Installation Guide for HVAC Systems 3. The length of a. For specific choices of duct material, and assuming air at standard temperature and pressure (STP), standard charts can be used to calculate the expected friction loss. The internal steel helix resists distortion during installation. To minimize field assembly costs, rectangular duct is supplied in lengths up to ten feet. The Flex-Flyte L-1 is a lightweight and flexible hose designed to handle air and fumes at low pressures and moderately high temperatures. The maximum duct temperature for plastic ducts shall not be greater than 150°F (66°C). from the end caps. Although typically SMACNA ’s HVAC Duct Construction Standards , Metal and Flexible , will. Attaining indicated. The duct will be 18 gage {The joints will be TDC/TDF {The joint length is 56 inches {The 140 inch side will be supported by 1” EMT conduit spaced 46 5/8” across the width and will be at each side of the joint and backing up the mid-panel reinforcement. Test and Verification Report on Gripple Hang-Fast Wire Duct Hanger System “Gripple Hang-Fast Wire Duct Hanger Systems Number 2, 3, and 4 as Acceptable Alternatives for Use with SMACNA HVAC Duct Construction Standards Metal and Flexible, Second Edition, 1995”. between flex duct and rigid metal duct when properly stretched and installed correctly. Keep the length and number of bends to the minimum. Use crimp joints with or without bead for joining round duct sizes 8 inch (200 mm) and smaller with crimp in direction of air flow. In general, maximum length shall be 6 feet or less. 1/4" to 24" diameters. SECTION 15900 – DUCTWORK AND ACCESSORIES 15900 Page 2 of 5 9/17/2010 2. The airstream surface is protected with JM’s exclusive reinforced coating system, a glass mat surface coated with Permacote® antimicrobial coating. SMACNA Fire, Smoke and Radiation Damper Installation Guide for HVAC Systems 3. T-10 through T-14 are restricted to 30 in. Effective Length The length of duct used for design purposes that includes the straight length of duct added to all the fitting equivalent lengths. length at 3 in. Flex-Flyte® L-1 | Hi-Tech Duravent Skip to main content. These guidelines will usually provide a maximum length for ductwork venting a dryer. The duct will be 18 gage {The joints will be TDC/TDF {The joint length is 56 inches {The 140 inch side will be supported by 1" EMT conduit spaced 46 5/8" across the width and will be at each side of the joint and backing up the mid-panel reinforcement. Transporting equipment and materials knowledge of safety requirements 8. density fiberglass flexible. Connect air devices to low pressure ductwork with five-foot maximum length of flexible duct and provide with a Flex-Flow elbow support. Airfoil manufactures over 100,000 lengths of duct a year and stocks over 20,000 lengths of insulated duct at all times. 5 centerline radius. Duct Sealing, Air Leakage Criteria, and Air Leakage Tests: Ducts shall be sealed as per duct sealing requirements of SMACNA Standards for duct pressure classes shown on the drawings. wg, to 36 in. Turning Vanes Fabricate from same metal gauge as duct in which they are installed. ၁ Duct (Sizing) ( ) Pressurized. If you are using a metal hose clamp, slide it over the inner core and push it back toward the rolled-up fiberglass portion. Retaining Angle a. Where fittings are used, the maximum length of the exhaust duct shall be reduced in accor-dance with Table 504. ) the rigid duct would leak about 8 CFM or 1. DUCT DESIGN, LEVEL 1: FUNDAMENTALS Distribution Systems 2 Space Availability The sizing criteria will often be defined by the space available to run the ductwork (Figure 1). Duct systems serving heating, cooling and ventilation equipment shall be fabricated in accordance with the provisions of this section and ACCA Manual D or. Flexible duct for pressure class 2 in. maximumpositivepressure. Field-fabricated and shop-fabricated metal and flexible duct constructions shall conform to the SMACNA HVAC Duct Construction Standards—Metal and Flexible except as allowed by Table M1601. any type which does not include automatic maximum temperature controls and where operating temperatures of 250°F (121°C) may be exceeded • In kitchen or fume exhaust ducts, or ducts conveying solids or corrosive gases • In any application where the duct liner may come in direct contact with liquid water (such as cooling coils,. SMACNA's "HVAC Duct Construction Standards - Metal and Flexible. The tables as shown herein are the SMACNA Tables with those interpretations already substi-tuted. A good rule of thumb is to provide a duct support no less than every 4 feet, and more frequently when using large-diameter flexible duct [4C], even when ducts are partially supported by framing members [4D]. Ductwork downstream of humidifiers shall be stainless steel for the length of dispersion. Air Flow Tests and Air Friction Data. Specify at least one (1) inch slack in these connections to insure that no vibration is transmitted from fan to ductwork. Adhere a single layer of indicated thickness of duct liner with at least 90 percent adhesive coverage at liner contact surface area. , which was the old standard for fan certification). By permitting the longer lengths, greater flexibility is achieved in laundry room placement within the building. wg, to 36 in. per ft (42 mm per m). They are made from an array of materials that range from polyurethane and thermoplastic rubber, to PVC and aluminum-coated fiberglass fabric, and are typically reinforced with a steel wire or rigid plastic helix, also. A 26 gage duct wall 20 inches wide, with a maximum reinforcement spacing of 12 feet and a 1 inch water gage static B 26 gage duct wall 22 inches wide, with a maximum reinforcement spacing of 10 feet and a 1/2 inch water gage static C 24 gage duct wall 22 inches wide with a 1 inch water gage static pressure. • Insulation R-value to meet Energy Code. , of ductwork. Another important unit to know is the friction loss rate of your ducts. accordance with SMACNA HVAC Duct Construction Standards, Metal and Flexible. Example Calculation Given a rectangular duct with the dimensions 915x700 going to a 700mm diameter fan connection with an airflow of 6. Every above ground duct installation needs hangers or supports of some kind. Design of Structures, Components, AP1000 European Equipment and Systems Design Control Document EPS-GW-GL-700 3A-2 Revision 1 3A. The designer has a great influence on these costs when specifying the duct system material, total CFM, system operating pressure, duct size and complexity, fan horsepower, control device and space requirements. 03 HANSEN HALL – LEVEL 300/400 RENOVATIONS CONSTRUCTION PACKAGE METAL DUCTS 233113 - 3 ards - Metal and Flexible," Chapter 3, "Round, Oval, and Flexible Duct," based on indicated static-pressure class unless otherwise indicated. static pressure class and 2500 FPM maximum velocity. Design of Flexible-duct Junction Boxes Current Standards • ASHRAE 2012 HVAC Systems and Equipment, Box Plenum Systems Using Flexible Duct – Constrains Box Width to 2-3x Entrance Width – Constrains Box Length to 2 x Box Width – Flat Pressure Loss = 0. Slide the flexible duct so that it overlaps the orifice tube 50 to 75 mm, and tighten clamp using a 8 mm nut driver. Accepted Industry Practice for Industrial Duct Construction, 2008. A duct system is a network of round or rectangular tubes—generally constructed of sheet metal, fiberglass board, or a flexible plasticand- wire composite—located within the walls, floors, and ceilings. Application Limitations. From corners of duct 4" (100mm) Along length of duct 16" (400mm) O. 1"wc or less (or a metal ductulator at *0. Every duct fitting adds a certain amount of restriction. Increase duct sizes gradually, not exceeding 15 degrees divergence wherever possible; maximum 30 degrees divergence upstream of equipment and 45 degrees convergence downstream. SMACNA's "HVAC Duct Construction Standards - Metal and Flexible. Fabricate in accordance with SMACNA Fibrous Glass Duct Construction Standards. Order DUCTMATE 6-1/2" x 50 ft. What is the maximum length for a range hood's ductwork? For optimum performance, make sure that the air duct is short and straight , with a maximum length of 50 linear feet. 0 duct and fittings must be used on all in heating, cooling and evaporative installations unless; (a) Duct is no more than 3 meters in length to an outlet or from an inlet then R 1. Flexible ducts should be supported by strapping having a minimum width of 1 1/2 inches at all contact points with the duct. The Level 2 Duct Design TDP will present many areas of design enhancement, such as SMACNA Duct Construction Standards, duct design code requirements, fitting selection using loss coefficients, avoiding acoustic issues, unique VA V system duct fea­ tures, and using life cycle cost analysis as a design criteria. Fiber Glass Duct Liner With Reinforced Coating System Description Linacoustic RC is a flexible duct liner insulation made from strong, glass fibers bonded with a thermosetting resin. Download with Google Download with Facebook or download with email. 5 inches B 25. Reading Guide - For duct sizes between, say, 651 mm and 700 mm, when the pressure class is 1” w. Standard elbows will have 1. Clearance between the sleeve and wall/flooropening shall be a maximum 1/8" per foot on height and width of sleeve to a maximum of 1-1/2" (e. The standard gauges also required by SMACNA (2005) are also required; this is standard practice for Lindab. Air Duct Council (ADC) The Air Duct Council (formerly the Air Diffusion Council) represents North America's leading manufacturers of Flexible Air Ducts and Air Connectors. Most technicians are skeptical about these numbers, especially on the Return air side of the system. Sizing of the ductwork is calculated using Manual D. Fibrous-Glass Duct Liner: Comply with ASTM C 1071, NFPA 90A, or NFPA 90B; and with NAIMA AH124, "Fibrous Glass Duct Liner Standard. The smooth, black, acrylic- coated surfaces of the Permacote Linacoustic HP shall face the airstream. Packaging: 1 section per poly-bag or carton. The maximum installed length of a flexible air connector is?. 3 Leakage test procedures shall follow the outlines and classifications in the SMACNA HVAC Duct Leakage Test manual. maximum recommended air quantity (litres per second) flexible duct diameter (mm) 44 l/s Ø 150 92 l/s Ø 200 170 l/s Ø 250 275 l/s Ø 300 385 l/s Ø 350 503 l/s Ø 400 636 l/s Ø 450 785 l/s Ø 500 950 l/s Ø 550 revision 14/04/03 b-ds 1 flex sizing flexible ductwork flexible duct sizing guide. Rectangular ducts with duct lagging are often ineffective in reducing duct breakout noise. Aerocel® EPDM elastomeric sheet is flexible and easy to use for a wide variety of jobs including large air ducts and inside air handling panels. Replacing a system of an air duct will depend on the type of ducts used like materials and flexibility as well as the length and local rates. The length of a. Airflow – Part 1. KINETICS™ Pipe & Duct Seismic Application Manual MAXIMUM UN-STIFFENED HANGER ROD LENGTH FOR 45° < A 60° PAGE 1 of 7 SECTION - A5. Duct Design Presented by Dave Janquart 2. Air duct calculator or “ductalator” sizing is acceptable when all other guidelines herein are adhered to. Two 45° turns within the duct length should be. Metallic Silver Polyethylene Duct Tape item(s) added to Cart Checkout Now. Select the item you would like to order by entering the quantity of the item you would like to receive. He recommends asking the duct supplier to email you the mandatory Flexible Duct Compliance Report Summary for each type of flexible duct being supplied on a job. (2) SMACNA Fibrous Glass Duct Construction Standard (3) SMACNA HVAC Duct Construction Standards — Metal and Flexible (4) SMACNA HVAC Air Duct Leakage Test Manual 4. SMACNA - 3. Fibrous-Glass Duct Liner: Comply with ASTM C 1071, NFPA 90A, or NFPA 90B; and with NAIMA AH124, "Fibrous Glass Duct Liner Standard. 5 times the diameter. Straight Flexible Dryer vent hoses that are run in a straight line from the dryer exhaust to the outdoors provide the best ventilation and reduce the likelihood of trapped lint. concrete advice on sizing medium-pressure VAV duct mains, the EDR. The maximum multi-section is 108"w and 108"h (2743mm x 2743mm) up to 36 square feet (3. The inner lining of these flex duct branches have been attached to the collars, but they have not been sealed 30 Figure 39. A duct system is a network of round or rectangular tubes—generally constructed of sheet metal, fiberglass board, or a flexible plasticand- wire composite—located within the walls, floors, and ceilings. This helps your contractor determine the static pressure for your unit throughout the length of your ducts—another size measurement that affects the overall air flow from your system. Sometimes, however, hurried installations create poor-quality results - as they can for any HVACR product. When used in duct lining applications, SMACNA duct lining practices are to be used for gluing and pinning Aerocel® to the sheet metal. All else being equal, going up one size in flex duct will accomplish about the same thing as a sheet metal duct. How to place an order with NYC SMACNA: Complete Part 1. Determine the number of 90° turns needed for your installation. • RSC is a “Scotty” take-off. flex duct sizing max length meticulous. method(s) b. per ft (42 mm per m). The trunk that serves these two ducts needs to be able to deliver 72 + 197 = 269 cfm. US Duct offers a wide variety of hangers to accomplish the task. Exception:Where the make and model of the clothes dryer to be installed is known and the manufacturers installation instructions for such dryer are provided to the code official, the maximum length of the exhaust duct, including any transition duct, shall be permitted. The snap lock sheet metal duct pipe is ready to be assembled. Flexible Duct Materials. Flexible ducts shall consist of an exterior reinforced laminated vapor barrier, 1½" thick -. Flex Duct Type: This is the default type for flexible duct for branch ductwork (Flex Duct Round : Flex - Round, or None). Shop imperial 6-in x 96-in aluminum semi-rigid flexible duct in the flexible duct section of Lowes. This table shows some typical duct sizes and the weight that can be saved by changing gage per certified test: SMACNA Table Variation permitted per certified test. static, we require a ROLAMATE 'E' Class Flange and duct gauge of 26. Test and Verification Report on Gripple Hang-Fast Wire Duct Hanger System “Gripple Hang-Fast Wire Duct Hanger Systems Number 2, 3, and 4 as Acceptable Alternatives for Use with SMACNA HVAC Duct Construction Standards Metal and Flexible, Second Edition, 1995”. Allowable Leakage based on SMACNA Leakage Class SMACNA and NEBB recommend use of leakage class for specifying allowable leakage. Required fields are denoted with an asterisk (*). All comparisons of cost and performance in this example are based on a design pressure of 2. Insulation where required, shall be on the exterior of the duct. non-metallic duct, with maximum O. SMACNA HVAC Duct Systems Inspection Guide 7. ASHRAE DUCT DESIGN. Maximum Flex Duct Length: This is the longest length of a flexible duct segment that can be used in routing solutions for branch ductwork. Peripheral systems (single or double duct) a. Advantages Improves Indoor Building Environment. 01 Work Included A. Install horizontal flex duct hangers at least every 4 feet (1. As discussed in our Hvac for Beginners main page, each component of a forced air system, from the filter to each branch duct, adds a certain amount of restriction to the airflow of that system. 28 inH2O/100ft (2. Airfoil manufactures over 100,000 lengths of duct a year and stocks over 20,000 lengths of insulated duct at all times. In some applications, bracing may be required. static pressure class and 4000 FPM maximum velocity. A 24 inch by 16 inch rectangular duct with a 1. Main return air duct risers from the return fan upstream to the fire dampers or. Any duct length over 50 ft is recommended to use a larger diameter duct size. Mighty Tough Fibered Sealants are a UL Listed 181B-M, High Velocity, fast drying, non-flammable, high-quality, flexible water based duct sealant with excellent adhesion, specially formulated to meet SMACNA and local codes to pressure-seal all types of HVAC sheet metal air duct systems, and UL Listed flexible duct. maximum recommended air quantity (litres per second) flexible duct diameter (mm) 44 l/s Ø 150 92 l/s Ø 200 170 l/s Ø 250 275 l/s Ø 300 385 l/s Ø 350 503 l/s Ø 400 636 l/s Ø 450 785 l/s Ø 500 950 l/s Ø 550 revision 14/04/03 b-ds 1 flex sizing flexible ductwork flexible duct sizing guide. Do not use flexible ducts to change directions. The standard contains tables and pages: 390. Where space is restricted, the maximum angle of 30 deg. They utilize a narrower section of 24G to 28G G-90 galvanized steel for easy bending, is available in a variety of special fabrics and excels in isolating vibrations produced by air handling units, fans, blowers and other residential HVAC equipment. The maximum sag the SMACNA standard calls for is 1 •2 in. , 15' for elbows, 30' for a termination fitting, standard temperature and pressure, and roughness factors of 0. Carlos Martinez. band) quick release s. It is able to endure temperatures between -4°F and +176°F. , 2005,it was found that in some tests, the Ward Angles (E,H and J) permitted a more liberal interpretation of the SMACNA Tables. ATCO's UPC #037 is a UL 181, Class 1 Air Duct and is manufactured with a reinforced metallized polyester jacket. Buy GREENSEAM Reducer,7" x 5" Duct Size GRR7P5PGA24 at Walmart. For each elbow, add 15 feet. To minimize field assembly costs, rectangular duct is supplied in lengths up to ten feet. Where fittings are used, the maximum length of the exhaust duct shall be reduced in accor-dance with Table 504. In most cases, local regulations limit their length to a maximum of 1. Not to mention that flex duct costs significantly less than other types of duct systems and is easier to store and transport. Most technicians are skeptical about these numbers, especially on the Return air side of the system. Steel Air Duct – Min 0. The diameter of fittings shall be appropriated for mating with sections of the straight duct, equipment, and air terminals to which they connect. Do not use flexible ducts to change directions. 810 Cold air boot, collar, duct 45- 65' EL AIR FLOW DYNAMICS & DUCT SIZING REFERENCE GUIDE SUPPLY OR RETURN DUCT SIZE/CAPACITY (. org 5-12 ASHRAE Minimum Duct Seal Level Duct Location Duct splitter vanes (Source: ASHRAE Handbook Fundamentals 2001) ASHRAE duct 48” 2” ဂ v m ) (၄) 4:1 m m m mm (၅) m ၅. length at 3 in. 5 inch flexible liner will have exterior dimensions of? A 24.